Building unit for safety ski binding

ABSTRACT

The invention relates to a holding unit, in particular a toe unit, for safety ski bindings, which has a sole hold-down arranged on a bolt and two angle levers pivotably mounted about a spindle each, arranged on a supporting member, the angle levers being adapted to swivel out to the side against the force of a spring. The sole hold-down is adapted to move upwards against the force of the spring when there is a force acting vertically upwards on it, via a compensating lever, which bears against one of the angle levers each either directly or with an intermediate lever interposed. The bolt is guided displaceably in the vertical direction and, if there is an overload, is acted on by a wedge element which is guided on the supporting member and against which the ski boot bears. 
     In this arrangement there is a compensation for the frictional forces additionally occuring on the sole hold-down in the event of a twisting fall both backwards and forwards. 
     According to the invention, to support the ski boot, the wedge element is equipped with two support rollers and is connected to a guide bolt, which is arranged longitudinally movably in a sleeve-shaped tie rod acting on the angle levers.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a holding unit, in particular a toe unit, forsafety ski bindings, which has a sole hold-down arranged on a bolt andtwo angle levers. The angle levers are pivotably mounted about a spindleeach, arranged on a supporting member, and being adapted to swivel outto the side against the force of a spring. The sole hold-down is adaptedto move upwards against the force of the spring when there is a forceacting vertically on it and away from the upper side of the ski(upwards), via a compensating lever, which is designed as a two-armedlever and is mounted to swivel about a bearing spindle arranged on thesupporting member. The compensating lever has at least on its one armtwo preferably mutually parallel running arm sections, of which each, atleast in the descent position of the holding unit, bears against one ofthe angle levers each either directly or with an intermediate leverinterposed. The compensating lever is supported resiliently by its otherarm with respect to the sole hold-down and is connected articulatedly tothe bolt. The bolt is guided displaceably in the vertical direction, therange of movement of the sole hold-down being limited upwards by a stop,and there being guided displaceably in the longitudinal direction of theski on the supporting member a wedge element. When the ski boot fittedinto the holding unit, the wedge element bears against the ski bootsole. At least one sloping surface of the wedge element interacts withat least one sloping surface of a support part, which is secured againstdisplacement at the bolt supporting the sole hold down.

2. Description of the Related Art

According to Austrian Patent No 372.616, a tie rod is provided, whichpasses through the supporting member, and acts at one end against thetwo angle levers and is acted upon at the other end by a spring whichcan be adjusted in its pretension by means of an adjusting screw.

According to the main patent, in a toe unit, a compensation of thefrictional forces additionally occurring during a twisting fall bothbackwards and forwards on the sole hold-down is ensured. Consequently, aconstant releasing force is assured for all possible twisting falldirections.

However, with this solution it was not possible to also initiate thecompensation whenever an excessive force loading occurred only in thelongitudinal direction of the ski, since the two lateral angle leverswere blocked against such a force due to their design. The ski bootsole, in the running position, bore against regions of the individualangle levers running within the two bolts designed as spindles, so thatthe levers were acted upon by the ski boot sole in the closingdirection. Only when a deflection of the one angle lever was initiatedand the force component acting in the longitudinal direction of the skialready overcame the blocking angle was a compensation initiated - forexample in the event of a forward twisting fall.

SUMMARY OF THE INVENTION

By the present invention it is intended that a compensation of thefrictional forces additionally occurring between the ski boot sole andthe angle levers also takes place when forces act exclusively in thelongitudinal direction of the ski.

The features of the present invention serve to separate the support theski boot sole on the angle levers and on the wedge element. As a result,the ski boot can also displace the wedge element when a force actsexclusively in the direction of the longitudinal axis of the ski, thewedge element for its part displacing in a known way the support partand, via the latter, the bolt in the vertical direction. In this mannerthe compensating lever is swivelled and the two angle levers are pushedslightly apart against the force of the spring. The angle levers arethus relieved, thereby facilitating the release of the ski boot. Hence,as desired, a compensation also takes place of those frictional forceswhich additionally occur when there is an overloading acting exclusivelyin the longitudinal direction of the ski between the angle levers andthe ski boot sole. If this overloading stops without a release at thesides having taken place, the system returns to the initial position.The ski boot sole is again also held by the angle levers.

The features of the present invention also ensure a centering of the skiboot in the holding unit during running even when, due to a forwardmovement of the ski boot, the two angle levers have opened and thusreleased the ski boot at the sides.

The present invention also has the effect of achieving a particularlycompact design of the holding unit.

Further, the invention insures the guidance of the wedge element withoutuse of additional components.

Particularly favorable developments of the design and the mounting oftie rod and guide bolt are produced by the invention.

In accordance with the present invention there is provided a simple andreliable connection of the guide bolt to the wedge element and anarrangement of the wedge element relative to the slide.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features, advantages and details of the invention are nowdescribed in more detail with reference to the drawing, which representsan exemplary embodiment. In the drawing;

FIGS. 1 and 2 show the toe unit according to the invention in therunning position of FIG. 1 being a side view in section and FIG. 2 beinga section along the line II-II of FIG. 1;

FIGS. 3 and 4 correspond to FIGS. 1 and 2 which show the toe unit aforce acting on the toe unit in the longitudinal direction of the ski,FIG. 3 being a side view in section and FIG. 4 being a section along theline IV-IV in FIG. 3;

FIG. 5 shows a compensating lever of the present invention in obliqueview, FIG. 6 is a detail portion of FIG. 2 and FIG. 7 is a detailed viewof a portion of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

On ski 1, a supporting member 14 is fastened by its region designed assupporting plate 14a by means of screws 2. The supporting member 14 mayalso be arranged on a baseplate, which is displaceable in thelongitudinal direction of the ski in a way known per se on a guide railfixed to the ski and adapted to lock in various positions. Thesupporting member 14 bears angle levers 15, known per se, by means ofbolts 16 designed as spindles, which levers are mounted so as to swivelabout the bolts. At its end region facing the ski tip, the supportingmember 14 is designed as a wall 14c which is substantially at a rightangle to the upper side of the ski 1 and is made in its upper region asa bearing sleeve 14b. Bearing sleeve 14b forms, by means of a bearingspindle 17, a swiveling connection to a compensating lever 10 designedas a two-armed lever. This structure will be described in further detailwith reference to FIG. 5.

A spring 5 acts with its one end on the wall 14c of the supportingmember 14, the other end of the spring 5 being supported in asleeve-shaped abutment 8. The pretension of the spring 5 is adjustablein a way known per se by means of an adjusting screw 7. The respectivespring adjustment can be read off on a display device 9, known per se,indicated in FIGS. 1 and 3.

A sleeve-shaped tie rod 6, through which a guide bolt 6a passes, isarranged coaxially to the compression spring 5, is anchored at one endin the adjusting screw 7 and is fastened at the other end on a slide 13,which acts on the angle levers 15. Considered in its longitudinaldirection and as known per se, the tie rod 6 is subdivided into twosections, of which one section is provided with an external thread andengages in the adjusting screw 7 and the second section is designed witha smooth outer surface and is guided longitudinally displaceably in aguide bush 28 fixed in the wall 14c of the supporting member 14. Theguide bush simultaneously serves as abutment for the spring 5 and theguide bolt 6a is displaceably mounted within tie rod 6 for longitudinalmovement. The toe unit is surrounded for the most part by a housing 25.

A sole hold-down 22 for the ski boot sole 11a of a ski boot 11 ismounted pivotably on a bolt 21, the compensating lever 10 also beingarranged on the bolt 21 by means of its one arm, which is designed as abar-like fastening part 10b. Between the sole hold-down 22 and thefastening part 10b there are arranged a flexible element 23 and aretaining ring 24. The upper section 21a of the bolt 21 is provided witha thread, which engages in a counterthread of the sole hold-down 22, andwith a screw head, whereby the sole hold-down 22 can be adapted to avariety of ski boot sole heights. The upper section 21a of the bolt 21is adjoined in the direction of the upper side of the ski by a shortmiddle section 21b having a smooth surface. Middle section 21b isadjoined by a lower section 21c of a smaller diameter, the lower section21c likewise having a smooth surface. The lower section 21c of the bolt21 passes through a bore 14d of the supporting plate 14a, which has inthis region an inverted U-shaped, upwardly reduced embossing 14e. Thelower-most end of the bolt 21 is provided with a rivet head 21d, thediameter of which is greater than the diameter of the bore 14d.

As is evident in detail from FIG. 5, the compensating lever 10,considered in side view, is shaped as a two-armed lever, the one,approximately horizontally running arm of which consists of thefastening part 10b and the other, substantially vertically running arm10a has two, approximately mutually parallel running arm sectionsconsisting of two subsections in each case, 10c, 10e and 10d, 10frespectively. In this arrangement, the first two subsections 10c, 10d,adjoining the fastening part 10b, run at an acute angle α to thefastening part 10b, whereas the second, freely projecting subsections10e, 10f, adjoining the first two sections 10c, 10d are bent off withrespect to the said first subsections at an angle β. The size of theindividual angles α, β is chosen such that, in the running position ofthe toe unit, the two freely projecting subsections 10e, 10f runsubstantially vertically, pass through clearances, not designated in anymore detail, in the wall 14c of the supporting member 14 and bear eachagainst one of the angle levers 15. The bearing spindle 17 passesthrough the first two subsections 10c, 10d of the individual armsections 10c, 10e and 10d, 10f of the compensating lever 10, which isarticulated so as to swivel via the bearing spindle 17 on the bearingsleeve 14b of the supporting member 14.

On the upper side of the embossing 14e of the supporting member 14 thereis displaceably guided in a way still to be described in more detail awedge element 27, connected to the guide bolt 6a of the tie rod 6 bymeans of its front wall 27i. The wedge element 27 bears on its sidefacing the ski boot 11 two axis bolts 27a, on which there is arranged ineach case a support roller 27b, against which the ski boot sole 11abears--when the ski boot 11 is fitted into the holding unit. The wedgeelement 27 has between its two support rollers 27b a clearance 27d,running in the longitudinal direction of the ski, which is provided forreceiving the bolt 21 and allows a longitudinal displacement of thewedge element 27 on the supporting member 14 relative to the bolt 21. Inthis case, the two side walls 27e, 27f of the clearance 27d run from thediameter of the bolt 21 in the direction of the ski boot 11 in a planein each case and substantially parallel to each other, thereby producinga guide for the wedge element 27 on the bolt 21. The two subregions 27g,27h, adjoining the clearance 27d, of the wedge element 27 are providedwith sloping surfaces 27c, each one running at an acute angle γ ofapproximately 30° with respect to the upper side of the ski (cf. FIG.7). On the sloping surfaces 27c of the wedge element 27 there restsloping surfaces 26a of a support part 26. The support part 26 is pushedonto the lower section 21c of the bolt 21 and is held in position on thebolt 21 at one end by the wedge element 27 and at the other end by theflange-like widened diameter of the middle section 21b of the bolt 21.In this arrangement, the wedge element 27 has the upright front wall27i, in which the guide bolt 6a is anchored, on its side facing awayfrom the two axis bolts 27a.

The movement sequence in the event of a purely horizontal release is asfollows: if one of the angle levers 15 is horizontally loaded, itswivels outwards about its associated bolt 16. During this swivelingmovement, the slide 13 acting on the angle lever 15 is displacedtogether with the tie rod 6, the adjusting screw 7 and the abutment 8 inthe longitudinal direction of the ski towards the sole hold-down 22, andthe spring 5 is compressed.

If a backward twisting fall takes place, the ski boot 11 acts with avertically upwardly directed force on the sole hold-down 22. By thisforce effect, the compensating lever 10, connected to the sole hold-down22, swivels counterclockwise about the bearing spindle 17, the two freesubsections 10e, 10f of the compensating lever 10 acting upon the anglelevers 15, so that they swivel outwards about their bolts 16. Theswiveling movement of the angle levers 15 has as a consequence a slidemovement, as occurs in the case of a horizontal release, and the spring5 is compressed. The movement of the sole hold-down 22, or the swivelingrange of the compensating lever 10, is limited by the stopping of therivet head 21d of the bolt 21 against the embossing 14e of thesupporting plate 14. The resilient element 23 allows the swivelingmovement of the compensating lever 10 without moving the sole hold-down22 out of its position relative to the upper side of the ski.

In the event of a forward twisting fall, the ski boot sole 11a acts bothon one of the angle levers 15 and on the wedge element 27 and displacesthe latter on the supporting member 14 in the direction of the ski tip.The support part 26, with it the bolt 21, is moved upwards via themutually interacting sloping surfaces 27a of the wedge element 27 and26a of the support part 26. The entrainment of the bolt 21 is ensured bythe middle section 21b of the bolt 21. As a result, the compensatinglever 10, connected to the sole hold-down 22, swivels counterclockwiseabout the bearing spindle 17, the two arm sections 10e, 10f of thecompensating lever 10 act on the angle levers 15, so that the latterswivel outwards about the bolts 16. The movement sequence taking placeabove the compensating lever 10 consequently corresponds to thatoccurring in the case of a backward twisting fall, as has already beendescribed.

Consequently, the additional frictional force occurring both in theevent of a backward twisting fall and in the event of a forward twistingfall between the ski boot sole 11a and the angle levers 15 iscompensated for by the facilitated release of the angle levers 15bearing laterally against the ski boot 11, the releasing force thusremaining constant, i.e. it corresponds to that of a purely horizontalrelease. These measures are known per se from the main patent and arerealized, as described, also in the case of the present solution.

As a result of the development according to the invention, it is ensuredthat a compensation is also initiated when there is a pure forwardpushing movement of the ski boot 11. This occurs in the event of a pureforward fall, because displacement of the wedge element 27 serves toswivel the two angle levers 15 in the way described in the case of aforward twisting fall even if neither of the two angle levers 15 isacted on by the ski boot 11, cf. FIGS. 3 and 4. In this case, the skiboot 11 is held centered only by the two support rollers 27b of thewedge element 27, as evident from FIG. 4. Evident from FIG. 6 is thecenter-to-center distance a of the two axis bolts 27a and the chordheight h. The center-to-center distance a is 30-36 mm, the chord heighth, i.e. the distance between the arc section of the ski boot sole 11aand the tangent to the boot of the two support rollers 27b, measured inthe longitudinal axis of the holding unit, is 1.5-2.5 mm.

In the case of a toe unit according to the invention, there is thereforea constant releasing force in all possible releasing directions. Thefrictional forces occurring between the ski boot sole 11a and the solehold-down 22, or the angle levers 15, are without influence on thereleasing forces.

The mutually interacting sloping surfaces 26a, 27c of the support part26 and of the wedge element 27 are, in an advantageous way, coated witha material for reducing the sliding friction between these parts. Thefriction occurring between the underside 27a of the wedge element 27 andthe upper side of the supporting member 14 can also be reduced by thesecomponents being coated or made with a friction-reducing material. Theinclination of the sloping surfaces 26a, 27c relative to the upper sideof the ski determines the extent of the force acting in the longitudinaldirection of the ski on the compensating lever 10 and transferred fromthe latter onto the angle levers 15. In this respect, the designer isgiven a certain freedom, depending on the further design of the holdingunit.

The invention is not restricted to the exemplary embodiment represented,in particular not to the toe unit described. The compensating lever andthe wedge element interacting with the support part can be arranged onany toe unit having angle levers.

Various modifications are conceivable without departing from the scopeof protection. The resilient element may also be arranged in the regionbetween the compensating lever and that region of the supporting memberon which the bolts of the angle levers are mounted. If the holding unitis arranged on a guide rail, the formation of an embossing on thesupporting plate becomes superfluous, since there is sufficient spacebetween the latter and the guide rail for the vertical movement of thestop of the bolt. To limit the vertical movement of the bolt, or of thesole hold-down, a stop could also be provided, for example on thehousing.

We claim:
 1. A toe holding unit for a safety ski binding,comprising:spring means for exerting sole holding forces on variousportions of the ski binding; a bolt; a sole hold-down moveable on saidbolt in a substantially vertical direction with respect to an uppersurface of a ski; two angle levers for exerting lateral holding forceson the sole of a ski boot, said angle levers disposed in the holdingunit for pivotal movement in a first direction toward a ski boot, and ina second direction away from a ski boot against the force of said springmeans; a compensating lever connected to said spring means and having afirst arm connected to an end of said bolt, said compensating lever alsohaving a second arm including two arm sections, each of said armsections for operative engagement with one of said two angle levers,said spring means for urging said first arm of said compensating levertoward said hold-down to maintain said hold-down in a sole holdingposition; a support part having a sloping surface, said support partbeing operatively connected to said compensating lever through saidbolt; and a wedge element connected to said spring means and having atleast one sloping surface for engagement with the sloping surface of thesupport part, the wedge element including two axis bolts each having aroller mounted thereon for bearing against the sole of a ski boot, saidsloping surface of said wedge element for acting against the slopedsurface of the support part to thereby urge the compensating lever to areleasing position in response to a force exerted on the wedge elementthrough the rollers.
 2. The holding unit as set forth in claim 1,wherein a center-to-center distance between the two axis bolts is 30-36mm, and wherein, with a ski boot fitted in the holding unit, the chordheight, being the distance between a line tangent to a tip of the soleextending transversely to the longitudinal direction of the ski and astraight line running parallel to the tangent line through points ofcontact of the two support rollers to the ski boot sole is 1.5-2.5 mm.3. The holding unit as set forth in claim 1 or 2, wherein a clearancefor receiving said bolt is formed between the two support rollers of thewedge element, the clearance extending in a longitudinal direction ofthe holding unit and being opened in the direction of the ski boot sole.4. The holding unit as set forth in claim 3, wherein the clearance isrounded on a side facing away from the ski boot to correspond to anouter wall of the bolt, and wherein two side walls of the wedge elementadjoining the rounded portion of the clearance extend substantiallyparallel to each other, and wherein said side walls serve as guides forthe wedge element in the longitudinal direction of the ski on the outerwall of the bolt.
 5. The holding unit as set forth in claim 1, whereinthe spring means includes an adjusting screw, a spring, and a tie rod,the tie rod including two sections, one of said sections being providedwith an external thread for engaging the adjusting screw and the secondsection including a smooth outer surface that is fastened on a slide,which acts on the angle levers, wherein the holding unit furtherincludes a guide bush and a supporting member for supporting said guidebush, the tie rod being guided in said guide bush, and the guide bushserving as abutment for the spring.
 6. The holding unit as set forth inclaim 5, wherein the wedge element has on a side facing away from thetwo axis bolts an upright front wall in which an end portion of the tierod is anchored, and wherein the upright front wall is spaced from theangle levers to permit unhindered pivotal movement of the angle levers.7. A toe holding unit for a safety ski binding, comprising:a solehold-down moveable in a substantially vertical direction with respect toan upper surface of a ski, for contacting the sole of a ski boot; twoangle levers disposed in the toe holding unit for exerting lateralholding forces on the sole of a ski boot, said angle levers adapted forpivotal movement toward and away from a ski boot; a compensating leverconnected to an end of said bolt and having a first arm for engagementwith said hold-down, and a second arm including two arm sections, eachof said arm sections for operative engagement with one of said two anglelevers; spring means for urging said first arm of said compensatinglever toward said hold-down to move said hold-down to a sole holdingposition; a support part having a sloping surface, said support partbeing operatively connected to said compensating lever; and a wedgeelement having at least one sloping surface for engagement with thesloping surface of the support part, and having a portion for bearingagainst the sole of a ski boot, said sloped surface of said wedgeelement for acting against the sloped surface of the support part tothereby urge the compensating lever to a releasing position in responseto a force exerted on the wedge element through the sole of a ski boot.8. A toe holding unit as set forth in claim 1 further including anintermediate lever disposed between at least one of said angle leversand said compensating lever.
 9. A toe holding unit as set forth in claim1 wherein the bolt includes a surface extending transverse to itselongated axis, said support part having a portion for engaging saidtransverse surface.
 10. A toe holding unit as set forth in claim 1further including a supporting member having an opening disposed thereinfor receiving a distal end of the bolt, the bolt including a stopdisposed on its distal end for preventing the bolt from being removedfrom the opening of the support part.